<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>
    var sum=1;
    for(var i=20;i<=40;i++){
        if(i%2==0){
            sum*=i;
        }
    }
    console.log(sum);

    var count=0;
    for(var i=100;i<1000;i++){
        var a=i%10
        var b=parseInt(i/10%10)
        var c=parseInt(i/100)
        if(a**3+b**3+c**3==i){
            count++;
        }
    }
    console.log(count);


    var sam=0;
    for(var i=1;i<=100;i++){
        if(i%2==0){
            sam-=i;
        }
        if(i%2!=0){
            sam+=i;
        }
    }
    console.log(sam);
    


</script>